Low TSH and other stories.....: Can anyone give... - Thyroid UK

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Low TSH and other stories.....

Piglet1956 profile image
36 Replies

Can anyone give me a link to some research (I think one was carried out in Tayside) papers that show low TSH doesn't necessarily lead to increased risk of AF and stroke? I had been having palpitations and had a dizzy spell before Christmas so I had my bloods done by my GP. I think she will be trying to reduce my Levo dose from 100 to 75 as TSH is suppressed but the last time I was on 75 I felt terrible. I feel I need to be seen by an endo as none of my figures make sense. Here are the latest test results on 100mcg Levo -

TSH 0.09 (0.35-5)

T4 16.159% through range 9.0-21.0

T3 4.137% through range 3-6

These results are similar three other tests carried out between 30 June and 28 December 2021.

Vitamin and mineral levels also tested but results not yet available.

The last time I was on 75 my results were -

TSH 1.11 (0.35-5)

T4 14.647% through range 9.0-21.0

T3 wasn't tested as I was in normal range for TSH

I have GP and another doctor telling me I am at risk of AF and stroke If I stay on 100mcg of Levo and yet T4 and T3 levels are poor and there are numerous papers cited saying below range TSH is OK when medicated. I notice that Dr Anthony Toft's paper states that 'This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)' i.e. around 60% through the range my T3 is around half of what Toft would recommend so does that mean I am at risk of AF and stroke?

I am also not sure if my palpitations are due to the doctors worrying me!!

Please help . Thank you

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36 Replies
SlowDragon profile image
SlowDragonAdministrator

Low Ft3 can cause palpitations

Always test thyroid levels as early as possible in morning before eating or drinking anything other than water and last dose levothyroxine 24 hours before test

Do you always get same brand levothyroxine at each prescription …if yes….. which brand

What vitamin supplements are you currently taking

Looking at previous posts you have high thyroid antibodies and autoimmune thyroid disease confirmed

Have you had coeliac blood test done

Are you on strictly gluten free diet

Piglet1956 profile image
Piglet1956 in reply toSlowDragon

Thank you SlowDragon. All tests carries out 24 hours after last Levo dose and either at 9 or 9:30am (most recent was at 9:30am). I am not celiac but Im strictly gluten free. My antibodies are around 178 at the moment, reduced from around 1100 when first diagnosed 18 months ago so I feel pleased about that. Do you have a source that I can quote for low T3 also causing palpitations?

SlowDragon profile image
SlowDragonAdministrator in reply toPiglet1956

So as you are hashimoto’s and gluten intolerant, likely to need/benefit from addition of T3 prescribed alongside levothyroxine

Have you done Dio2 gene test?

thyroiduk.org/deiodinase-2-...

Can help get T3 prescribed on NHS assuming you test positive

Email Thyroid UK for list of recommended thyroid specialist endocrinologists who will prescribe T3

...NHS and Private

tukadmin@thyroiduk.org

Piglet1956 profile image
Piglet1956 in reply toSlowDragon

Yes I intend to have the DIO2 test done. Thx

SlowDragon profile image
SlowDragonAdministrator

academic.oup.com/jcem/artic...

Interestingly, patients with a serum TSH below the reference range, but not suppressed (0.04–0.4 mU/liter), had no increased risk of cardiovascular disease, dysrhythmias, or fractures. It is unfortunate that we did not have access to serum free T4 concentrations in these patients to ascertain whether they were above or within the laboratory reference range. However, our data indicate that it may be safe for patients to be on a dose of T4 that results in a low serum TSH concentration, as long as it is not suppressed at less than 0.03 mU/liter. Many patients report that they prefer such T4 doses (9, 10). Figure 2 indicates that the best outcomes appear to be associated with having a TSH within the lower end of the reference range.

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.

Most patients will feel well in that circumstance.

But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor



please email

tukadmin@thyroiduk.org

Office reopens tomorrow

Piglet1956 profile image
Piglet1956 in reply toSlowDragon

And thanks also for the article - its the one I was looking for.

in reply toSlowDragon

Thank you for this - I've recently had my dose reduced for a suppressed TSH, due a risk of osteoporosis and I've been meaning to research the risk. This article is a great first step.

SlowDragon profile image
SlowDragonAdministrator in reply to

Most important results are ALWAYS Ft3 followed by Ft4

Recommend getting FULL Thyroid And vitamin testing done minimum 6-8 weeks after any dose change or brand change in levothyroxine

ALWAYS test as early as possible in morning before eating or drinking anything other than water and last dose levothyroxine 24 hours before test

Low Ft3 can cause osteoporosis…..as can high Ft3

Osteoporosis and low Ft3

thyroidpatients.ca/2018/07/...

Essential to regularly retest vitamin levels, especially vitamin D

Vitamin D and magnesium for good bone healthy

What vitamin supplements are you currently taking

Hylda2 profile image
Hylda2

I always have TSH at 0.02 with T4 over the top. I have recently added in some T3 as my range is very low. I have AF but have discussed my range with my cardiologist and she was not at all bothered.

greygoose profile image
greygoose

'This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)' i.e. around 60% through the range my T3 is around half of what Toft would recommend so does that mean I am at risk of AF and stroke?

This is a bit confusing. When Toft says 'normal', he means somewhere within the range, be it 60%, 30%, 5% or whatever. By 'abnormal' he would mean over-range.

Also, Toft is talking about Total T3. Your result is a Free T3, so not the same thing, and can't be compared in any way.

So, no, your results in no way suggest that you are at risk of AF or stroke, even with a suppressed TSH. :)

Piglet1956 profile image
Piglet1956 in reply togreygoose

Now I am confused . So when Toft talks about most people feeling well when both T4 and T3 are in the upper part of the reference range he is referring to free T4 but Total T3? 🤦‍♀️😕And how would I ever know what my Total T3 is?

greygoose profile image
greygoose in reply toPiglet1956

Apparently so, yes. Toft is Scottish, and in Scotland they test the TT3 rather than the FT3, I'm lead to believe. In the rest of the UK, they test the FT3, if they test T3 at all. But, you really don't need to know what your TT3 is, it's a pretty useless test, don't know why they do it.

Piglet1956 profile image
Piglet1956 in reply togreygoose

I'm in Scotland and all my lab results are definitely for Free T3. But I guess TOFT may may have worked differently. I only get my FT3 tested when TSH is below the reference range!!

greygoose profile image
greygoose in reply toPiglet1956

What can I say? Lucky you? lol There are always exceptions to the rule? I only know what I read, I don't even live in the UK :)

But, you can tell by the ranges that yours is an FT3 and Toft was talking about a TT3.

DippyDame profile image
DippyDame in reply toPiglet1956

I'm in Scotland too and the only TT results I ever had were from an endo. GP labs are always FT. Also FT3 tests were stopped in Oct 2001 unless TSH suppressed....which it is permanently because I'm on high dose T3-only!!

Susieibbo301 profile image
Susieibbo301 in reply toDippyDame

Dear Dippy Dame, what do you call suppressed. I have TSH at .005 but my T3 and T4 are always mid range. I am on 100 levo and 10mg Lio. Many thanks. Susie

DippyDame profile image
DippyDame in reply toSusieibbo301

"Suppressed" is considered to be a result below the TSH reference range....but medics are far too reliant on TSH labs, I'll explain below.

I'm on high dose T3-only because I have a type of Thyroid Hormone Resistance and my TSH is on the floor because the pituitary recognises the high hormone level in the blood and sends a signal ( low TSH) to tell the thyroid gland to produce less hormone.

But...

TSH is not a reliable test on which to base dosing it does not show us the level of free T4 and T3 which we need as a guide to dosing. FT3 is the important lab, it is the active thyroid hormone required by every cell in the body in an adequate and constant supply.

I would rely on thyroid hormone levels FT4 and FT3 labs as a dosing guide....not the pituitary hormone level TSH.

If FT3 is in range you are very unlikely to be overmedicated.

If you feel well on your current dose don't be persuaded to change it on the basis of TSH!

This might help...

bmcendocrdisord.biomedcentr...

Time for a reassessment of the treatment of hypothyroidism

John E. M. Midgley, Anthony D. Toft, Rolf Larisch, Johannes W. Dietrich & Rudolf Hoermann

thyroidpatients.ca/2021/07/...

Piglet1956 profile image
Piglet1956 in reply toDippyDame

Thank you DippyDame. My current TSH is 0.09, FT4 is 59% through the range and FT3 37% through the range. Even with these I still have some hypo symptoms but new and the most worrying is palpitations mostly at night. I fear they will want me to reduce Levo from 100mcg to 75mcg without addressing the other symptoms.

DippyDame profile image
DippyDame in reply toPiglet1956

It looks as if your T4 to T3 conversion is poor.....high FT4 with low FT3The TSH result is just a red herring!!

You are undermedicated which is causing symptoms

Have you considered having the thyroid genetic test to check for the Dio2 variant

Medics can be reluctant to accept poor conversion on the basis of high FT4 with low FT3...although they should! But try that!

They are more likely to accept a positive Dio2 test prior to offering T3.

pubmed.ncbi.nlm.nih.gov/191...

Common variation in the DIO2 gene predicts baseline psychological well-being and response to combination thyroxine plus triiodothyronine therapy in hypothyroid patients

Vijay Panicker 1, Ponnusamy Saravanan, Bijay Vaidya, Jonathan Evans, Andrew T Hattersley, Timothy M Frayling, Colin M Dayan

thyroiduk.org/deiodinase-2-...

FT4 at 59% is still slightly on the low side....some/most people will need it to be higher

FT3 at 37% is far too low and most likely why you are having palpitations etc

You'll remember that FT3 is the important result and that every cell in the body needs to be saturated with an adequate and constant supply of T3....if T3 is low we suffer!

Important to ensure vit D, vit B12, folate and ferritin are optimal ...to support thyroid function

You could increase to 125mcg levo though I suspect this may still not produce enough T3....don't let them reduce your levo. Your FT3 will just drop further. Don't accept scaremongering about low TSH!

Then retest in 6 weeks...

Or, in your shoes, based on poor T4 to T3 conversion, I'd straight away push for the addition of T3....maybe 10mcg added to your 100mcg Levo.

For good health both Frees need to be somewhere approaching 75% through their respective ranges.

GPs don't initiate T3 medication so your best approach may be to ask for referral to an endo....and hope they are knowledgeable!

Just a few thoughts to consider.

Good luck and please keep us posted

Piglet1956 profile image
Piglet1956 in reply toDippyDame

Thank you again. I have a phone call with GP tomorrow which I’m dreading. Not had the thyroid convo with this particular one but no reason to expect she will be different to the others. I will have the DIO2 test done. Did you see an endo on NHS?

DippyDame profile image
DippyDame in reply toPiglet1956

Yes, I saw an NHS endo twice but it soon became clear he wasn't able to help me, so with the support of some experienced members here I decided to take control...lovely man but knowledge poor. He would never in a million years have prescribed the dose of T3 I need to function.

It turned out that I'm a fairly rare case ( it was a steep learning curve!) so don't let my experience put you off requesting an endo appointment...they should be able to help

You have every right to ask for a referral. While you wait for an appointment, it might take time, so ask this GP if she will consider giving you a trial of 125mcg ( "trial" dents their ego less than asking outright for more!!), that may help a little until you get some T3.

Hopefully this new GP is open minded ...quietly and politely stick to your guns. It's your health and we ( you) know our bodies better than anyone else...and yours is telling you it needs help! Use the info we've given you to state your case.

Make a list of what you want to ask/ say before you speak to this GP....that used to help me focus.

Good luck!

Purplebum profile image
Purplebum in reply toPiglet1956

I went through something similar last year where my TSH was under range 0.09 and levo reduced from 100 to 75 even though I protested. During the year I was also having issues with menopause and HRT. But to cut a long story short I had an appointment with GP in November and strongly put my case to which she said she'd write to Endo and I've now had my levo increased only slightly 100 & 75 alternate days. By the time this change happend my TSH was up to 2.3 in less than 12 months! Glad I protested.

Susieibbo301 profile image
Susieibbo301 in reply toDippyDame

Dear Dippy Dame,

Thank you so very much for this. Enormously helpful - have just tried to absorb it. I still have symptoms so maybe I need to experiment with other methods/medication.

Thank you so much again.

Best wishes, and happy new year to you. Susie

DippyDame profile image
DippyDame in reply toSusieibbo301

Hope it helps...good luck.

Stourie profile image
Stourie in reply togreygoose

I’m in Scotland and for years always had t3 checked too and it was always ft3. Jo xx

SlowDragon profile image
SlowDragonAdministrator in reply toPiglet1956

Scotland generally still tests Total T3 ….rather than Ft3

Annoying and pretty useless

DippyDame profile image
DippyDame in reply toSlowDragon

Always FT labs at my surgery in Scotland.

Smorzando profile image
Smorzando in reply toSlowDragon

My surgery gives TT3 results (rarely, but when the lab deigns to test T3 it's total rather than free). I'm in the Glasgow area.Dr Toft stated (it was in a video I watched on YouTube) that he thought Total T3 was the more useful test, actually, although I know that's an unpopular opinion around here!

Stourie profile image
Stourie in reply toSlowDragon

No they don’t. I’ve always had my ft3 checked for years until recently when they don’t check it at all. Jo xx

Piglet1956 profile image
Piglet1956

Thank you MorecambeBay. So if Im understanding this correctly my TSh would be considered low but not suppressed?

DippyDame profile image
DippyDame

Link to the Dundee Tears Study

pubmed.ncbi.nlm.nih.gov/269...

Liothyronine use in a 17 year observational population-based study - the tears study

Graham P Leese 1, Enrique Soto-Pedre 2, Louise A Donnelly 2

Piglet1956 profile image
Piglet1956 in reply toDippyDame

Thanks DippyDame. Interesting study.

Thalia_sredaf profile image
Thalia_sredaf

From Thyroid Patients Canada

facebook.com/groups/thyroid...

facebook.com/groups/thyroid...

Poniesrfun profile image
Poniesrfun

Effects of Long-Term Combination LT4 and LT3 Therapy for Improving Hypothyroidism and Overall Quality of Lifencbi.nlm.nih.gov/pmc/articl...

"None of the patients who had abnormally low TSH or elevated FT3 or FT4 levels had hospitalizations for arrhythmias or thyrotoxicosis."

I'm a thyroid cancer survivor, total thyroidectomy and my TSH has been undetectable for several years now. I do well with FT4 in the lower end of range and FT3 in the upper 75+ % of range.

Patti in AZ

Piglet1956 profile image
Piglet1956 in reply toPoniesrfun

That’s good to hear that you’re feeling well. Gives me hope. My sense is exactly what you and DippyDame and others suggest ie T3 is too low but I don’t know where to begin on that one.

Poniesrfun profile image
Poniesrfun in reply toPiglet1956

I take 2 grains of NDT (NP Thyroid brand) a day and occassionally take additional synthetic T3. I am in the US – my nurse practitioner orders my tests (TSH, FT4, FT3 and cancer markers calcitonin and CEA) and prescribes my meds. I long ago gave up on endos but did work with my cardiologist on finding a reasonably optimal dose. It was a lot of work - I tracked my hear rate and blood pressure, along with energy levels, several times a day for a few months while we experimented with different dosing that didn't worsen my pre-existing cardiac issues (chronic tachycardia) while keeping me functional.

Despite being a nurse I knew almost nothing about thyroid until I got thyroid cancer. I found most endos I encountered knew even less while many NP's, who work a lot with women's issues, are more up to date and understanding and actually understand how thyroid hormones work.

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